Nitrogen Balances of Young Women Fed the FAO Reference Pattern of Amino Acids and the Oat Pattern

Abstract
The nitrogen balances of 6 young women were determined when they were fed a semi-purified diet with the essential amino acids proportioned as in the FAO reference pattern based on tryptophan levels of 240, 160, and 200 mg daily. With this pattern the 240-mg tryptophan level most consistently supported nitrogen equilibrium or slight retention in all of the subjects. The 160-mg level caused all subjects to be in negative balance. At the 200-mg level three subjects approached nitrogen equilibrium. Following these levels the subjects were fed the amino acids in the proportions in which they occur in oats supplied first by purified amino acids and then by cooked rolled oats and based on 240 mg of tryptophan for three subjects and 200 mg for the other three subjects. When the FAO pattern and the oat pattern were supplied by purified amino acids and fed at the same tryptophan level, there were no significant differences among the nitrogen balances of the subjects. With the semi-purified diet that supplied about 9 gm of nitrogen daily by a combination of essential and nonessential amino acids, glycine, and the diammonium citrate, 0.6 to 0.7 gm of nitrogen from essential amino acids was necessary to maintain these subjects in approximate nitrogen equilibrium or slight retention.